Computers, Laptops & Tablets Accessories & Hardware 84 84 people found this article helpful Disadvantages of UEFI (Unified Extensible Firmware Interface) The Unified Extensible Firmware Interface loads before your operating system By Mark Kyrnin Writer Mark Kyrnin is a former Lifewire writer and computer networking and internet expert who also specializes in computer hardware. our editorial process LinkedIn Mark Kyrnin Updated November 26, 2019 ASUSTeK Accessories & Hardware Keyboards & Mice Monitors Cards HDD & SSD Printers & Scanners Raspberry Pi Tweet Share Email When you first turn on your computer system, it doesn't immediately start loading your operating system. It initiates the hardware through the Basic Input Output System or BIOS. This procedure allows the computer's various hardware components to properly communicate with one another. Once the Power On Self Test is completed, the BIOS then initiates the operating system's boot loader. This process has essentially remained the same for more than 20 years but the technology has recently changed. Most computers now use an initialization system called the Unified Extensible Firmware Interface. History of UEFI UEFI is an extension of the original Extensible Firmware Interface developed by Intel. Intel developed this new hardware and software interface system when the company launched the ill-fated Itanium server-processor lineup. Because of its advanced architecture and the limitations of the existing BIOS systems, engineers developed a new method for handing off the hardware to the operating system that would allow for greater flexibility. Because the Itanium wasn't a huge success, the EFI standards also languished for many years. In 2005, the Unified EFI Forum expanded upon the original specifications developed by Intel to produce a new standard for updating the hardware and software interface. This consortium includes companies such as AMD, Apple, Dell, HP, IBM, Intel, Lenovo, and Microsoft. Even two of the largest BIOS makers — American Megatrends Inc., and Pheonix Technologies — are members. What Is UEFI? The UEFI is a specification that defines how the hardware and software communicate within a computer system. The specification actually involves two aspects of this process known as boot services and runtime services. The boot services define how the hardware will initiate the software or operating system for loading. Runtime services skip the boot processor and load applications directly from the UEFI. This approach makes it act somewhat like a stripped-down operating system by launching a browser. While many call UEFI the death of BIOS, the system actually does not completely remove the BIOS from the hardware. The early specifications lacked any of the POST or configuration options. As a result, the system still requires the BIOS in order to achieve these two goals. The difference is that the BIOS will likely not have the same level of adjustment as is possible in existing BIOS-only systems. Benefits of UEFI The biggest benefit of UEFI is the lack of any specific hardware dependence. BIOS is specific to the x86 architecture. UEFI potentially allows for a personal computer to use a processor from a different vendor or that does not have the legacy x86 coding in it. The other major benefit to the UEFI is that it supports several operating systems without the need for a bootloader such as LILO or GRUB. Instead, the UEFI can automatically select the appropriate partition with the operating system and load from it. Both the hardware and the software must have the appropriate support for the UEFI specification. Finally, the UEFI offers much more user-friendly interfaces than the old text menus of the BIOS. This advantage makes adjustments to the system much easier for the end-user to make. In addition, the interface allows for applications such as a limited-use web browser or a mail client to be launched quickly rather than launching a full OS. Drawbacks of UEFI The biggest problem with UEFI is hardware and software support. In order for it to work properly, the hardware and operating system must both support the appropriate specification. This isn't as much of a challenge with the current Windows or macOS but older operating systems such as Windows XP do not support it.